Thread-cutting mechanism for sewing-machines



A. R. W000.

THREAD CUTTING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED OCT. I3. I9I5- 1,325,707. Patented Dec. 23,1919.

3 SHEETSSHEET I.

M r B as I Q 0 E g a 0. I I I E N N I v a N I? II 6 fI I a N I I A Q Q E N N 1 Q g N Q II 0 I 7 Q 3% N T s E Q 0 H I: I I N SI \Q I WITNESSES: I w NI/ENTOR g Y 446M 0 2 fl za V 0 5 y A. R. W000. v THREAD CUTTING MECHANISM FOR SEWING MACHINES.

"APPLICATION FILED OCT- I3, 1915.

1,325,707. Patented Dec. 23,1010.

3 SHEETS-SHEET 2.

'& WITNESSES: INVENTOR 10: PM [4T ORNEY A. R. WOOD.

THREAD cumws MECHANISM FOR SEWING MACHINES.

APPLICATION FILED 00113, 1915.

Patented Dec. 23, 1919.

3 SHEETQ-SHEET 3.

UNITED STATES PATENT OFFICE.

ALFRED R. WOOD, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, A CORPORATION OF NEW JERSEY.

THREAD-CUTTING MECHANISM FOR SEWING-MACHINES.

Application filed October 13, 1915.

To all whom it may concern:

Be it known that I, ALFRED R. WOOD, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Thread Cutting Mechanisms for Sewing-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to an improvement in thread-cutting devices designed especially for embodiment in sewin machines for stitching in a pattern or predetermined form, and more particularly in machines employing a traveling work-holder, such as buttonhole machines. It has for one ofits objects to provide for the quick retraction of the cutting element across the range of action of the stitch-forming mechanism. It has for further objects to provide a simple and effective cutting and nipping device for the thread and a cord secured to the fabric by the stitch-forming mechanism and to provide means for automatically timing the cutting operation to occur either at the completion of each stitching period or only once at the end of a plurality of consecutive stitching periods, as in the repeated stitching of a buttonhole.

While applicable in certain of its features to various types of sewing machines, the present improvement is designed particularly for embodiment in a straight-buttonhole stitching machine of the well known No. 71 Singer type such as is represented in the United States patent to E. B. Allen and J. C. Binge, No. 1,028,655, of June 4, 1912. In the preferred form of the improvement, the traveling work-holder provided with the usual needle-aperture has one side thereof provided with spaced thread-nipping and cutting elements cooperating with a compound nipping and cutting blade pivotally mounted upon the work-holder to perform operative movements between said ele ments and to carry into engagement therewith the needle-thread and the cord leading through the needle-aperture of the work-holder from the work respectively to the needle and to a cord-guide above the work-holder.

Specification of Letters Patent.

The thread-nipping section.

Patented Dec. 23, 1919.

Serial No. 55,599.

of the blade preferably has an outwardly flaring notch in its operative edge for gathering the needle-thread and cord and compressing them together against a shoulder formed in the edge of the needle-aperture toward which they are carried in the thread-cutting and nipping operation.

111 the production of buttonholes in firm materials such as cloth, a single stitching around the buttonhole is sufficient to give the proper strength, and the stitching thread and cord are therefore properly severed at the completion of each stitchin operation ot a series. In certain elastic or loosely woven materials, such as knit goods, a single convolution of the cord is insufficient to strengthen the material to resist the tendency to stretching and distortion of the buttonhole, and it has therefore been common to perform a second stitching operation continuous with the first so as to prop erly strengthen the buttonhole. In order to gain the full advantage of the second stitching operation, it is important that the cord remain uncut until the completion of the second stitching period.

As represented in the said patent, the cutting and nipping blade is connected with a spring-pressed push-rod which is given an endwise movement in opposition to its spring through the travel of the workholder for retraction of the blade preparatory to an operative movement thereof, such push-rod being maintained retracted by a latch which is tripped by a connection with the stop-motion. In the present embodiment of the improvement, the push-rod traveling with the work-holder has a range of endwise movement which is occupied consecutively or recurrently by a stop-member by which its motion is arrested while the work-holder continues its travel so as to produce the relative movement requisite for the setting of the nippin and cutting blade. The stop-member is pre erably mounted for rotation and is formed with a series of circularly disposed stop-lugs with intermediate spaces, ratchet mechanism bein provided for imparting thereto when esired a partial rotation for each stitch-forming period so as to present only one sto -lug for engagement with the push-rod or a plurality of stitching operations. By interrupting the action of the ratchet mechanism, the thread-cutting device may be set for operation at the end of each stitching period or may be prevented from action for consecutive stitching periods.

As the setting of the cutting and nipping blade is dependent upon the travel of the W01l{-l10lClGl, ample time is provided for the retraction of such blade in the feed of the work-holder for buttonholes of moderate length and longer. In order, however, to insure the retraction of the blade with sulficient promptness in the stitching of small buttonholes requiring a short travel of the work-holder, means are provided for moving the work-holder and stop-member simultaneously toward each other so as to accelerate the retractive movement of the push-rod, thereby insuring that the threadcutting and nipping operation will be performed as efiectively in the production of short buttonholcs as with longer buttonholes.

While the several characteristic features of the present improvement above described mutually contribute to the scope and eflec tiveness of the machine for various classes of work, it is evident that each or" such features is adapted for use independently of the others, and that they may be embodied in thread-cutting mechanism of difierent construction and type from that of the said patent.

The invention will be understood by reference to the accompanying drawings, in which Figure 1 is a front side elevation of a buttonhole sewing machine embodying thepresent improvements, and Fig. 2 a rearside elevation of the same. Fig. 3 is a plan representing the thread-cutting mechanism and parts of the machine operatively related thereto. Fig. iis a partial sectional elevation and Fig. 5 a bottom plan, upon a larger scale, of the means for the cutting device for a thread-cutting and nipping operation, the setting means being represented in full lines in mean position and in dotted lines in two diflerent positions. Figs. 6 and 7 are re spcctively top and bottom plan views of the work-clamping foot car ying the threadcutting and nipping elements, and Fig. 8 is a perspective view of the thread-nipping blade-section. Fig. 9 is a sectional elevation upon a still larger scale showing the portion of the work-clamping toot provided with cutting and nipping elements with the needle-thread and cord engaged thereby. Fig. 10 is an elevation representing the latchlever for. the push-rod and the means for operating it.

The machine represented in the accompanying drawings is provided with stitchformiing mechanism including a reciprocating and laterally jogging needle,'a work holder with feeding mechanism for imparting to it longitudinal feeding and side-shift movements relatively to the stitch-forming mechanism, a cord-guide with automatically controlled means for maintaining it in advance of the stitch-formin mechanism relatively to the direction of reed for laying a cord within the overseam produced by the stitch-forming mechanism, a stop-motion for controlling the period of operation of the StltCll-fOlDlll'lg and feeding mechanisms, and a buttonhole cutting device adapted to be operatively connected with and actuated by the stop-motion at the completion of each stitching period, all constructed substantially as shown and described in the said Patent No. 1,028,655. The machine is also provided with means similar in general constru'ction to that of the said patent for effecting simultaneously the cutting of the stitching threads and the cord at the completion of the buttonhole stitching operation.

The machine is constructed with a frame comprising the usual bed-plate 1 from which rises the hollow bracket-arm standard 2 having the lateral tubular arm 3 in the head a of which is journaled the reciprocating needle-bar 5 carryingnaled in the rocking stop-lever 13 tulcrumed The work-holder comprises the clampcheck or foot 15 formed with the rectangular needle-aperture l6 surrounded by the rib 17 having a serrated lower face normally resting upon the elongated tlH'OZtlplate 18 which is carried by the cross slideplate 19 fitted to a suitable transverse guide way of the bed-plate. Fitted to a suitable transverse guideway of the cross slide-plate is the longitudinal slide-plate 20 formed with an aperture 21 embracing the throatplate 18 and having secured upon its rearward end the extension-plate 22. Upon the plate 22 is fulcrumed by means of the pin 23 the rearward end of the clam1J-arm 2 1 forked at its forward end and pivotallv connected by means of the screw-pins with the clamping foot 15, the clamp-arm 21 being pressed downwardly by means of the spring 26 surrounding the post 27 rising from the extension-plate 22.

Fixed upon the upright feed-wheel shaft 28 beneath the bed-plate is the usual feedwheel 29 formed with the feed cam-groove 30 and side-shift cam-groove 31, the former being entered by the roller-stud 32 upon one arm of the bellcrank-lever 33 whose other arm is connected by'means of the pitman 3% with the longitudinal slide-plate 20. The cam-groove 31 is entered by the roller-stud 35 upon one end of the rock-lever 36 fulcrumed at 37 and having at its opposite end a pivotal connection 38 with the cross slideplate 19 Through the connections thus described the work-holder derives the requisite endwise and sidewise movements for the proper presentation of the work to the stitch-forming mechanism in the production of a straight buttonhole, well known means being provided for varying the lateral throw of the needle in the production of the side stitches and the barring stitches.

The stop-lever 13 is normally pressed backwardly by means of the spring 39 to throw the plunger-bar 12 into operative relation with the stopping cam 11, and the lever 13 has the usual forwardly extending arm 10 having pivotally attached thereto the rod 411 passing through the bed-plate and connected with a treadle by means of the chain 42 for tilting the stop-lever 13 in opposition to the spring 39. The rod 41 is detained in its lower position by engagement with the rearwardly extending arm of a spring-pressed latch-lever 43 whose forward arm lies in the path of movement of the tripping point 44 upon the periphery of the cam-wheel 29 which acts in the usual manner to trip the stop-motion to arrest the stitchforming and feeding mechanisms and to effect the actuation of the buttonhole cutting knife 45 through suitable connections therewith.

The cord-guiding arm 46 having the guide-eye 47 depends from the oscillatory carrier 18 in the form of a sector-pinion meshing with racleteeth 49 of the sectorplate 50 which is controlled in its operation by the cam 100 to maintain the cord-guide in proper relation with the needle as set forth more fully in the said Patent No. 1,028,655.

As represented more particularly in F 6. 7 and 9, the depending rib 17 of the clamping foot is cut away at one end and partly along the adjacent side at to receive the auxiliary plate secured in position by the fastening screws 5-1: and provided with the serrated rib 55, the plate being notched in its upper face to form with the lower face of the foot 15 a slot to receive the cutting and nipping blade composed of the overlapped sections 56 and 57, respectively.

The blade-sections 56 and 57 have their shanks perforated to receive the screw 58 by which they are clamped within a transverse seat in the flange 59 of a rocking pin 60 which is journaled in a bearing boss 61 upon the foot 15. The cutting blade-section 56 has a concavely curved operative edge which is sharpened at its lower face (Fig. 9) to cotipera'te with the similarly sharpened edge of the plate 53 at the end of the needleaperture 16 in cutting the thread. The superposed nipping blade-section 57 has a blunt operative edge formed with the outwardly flaring notch 62 and with a shallow groove extending across its thread-nipping face from the base of said notch. This blade acts in gathering and compressing the needle-thread and the cord in conjunction with the end of the needle-aperture in the foot 15, which is formed with an abrupt shoulder 64: which serves as a stop to detain the thread and cord while the blade continues its operative movement to embed one within the other preparatory to their being nipped between the faces of the blade and the foot 15. As the plate 53 is secured to the bottom of the foot 15 remotely from the thread-cutting and nipping position. it is adapted to yield slightly to avoid injuriously crushing the thread and cord in the described nipping action.

The rocking pin 60 hasupon its upper end the cranl-:-arm 65 which is pivotally connected with the downwardly offset forward portion of the push-rod 66 slidingly journaled in its rearward portion within an angle-plate 67 sustained by the clamp-arm 2st. The push-rod 66 has fixed thereon the thrust collar 68 between which and the angle-plate 67 is preferably interposed a soft washer 69 upon which the collar 68 is maintained normally seated by means of a spring 70 connected with the latter at one end and at the opposite end with a collar 71 fixed upon the rod 66. In its action upon the push-rod 66, the spring 70 imparts operative thread-cutting and nipping movements to the blade 56 57 and maintains the latter yieldiugly in its advance or nipping position wherein the edge of the blade 57 adjacent the head of one of the spaing screw-pins 72 intermediate the lower face of the clamping foot and the plate as represented in dotted lines in Fig. 3.

T appcd into the front side of the stand: ard 2 is a stud-pin 73 upon which is fitted the apertured s1 ide-block 74 provided at its 'earward end with the boss 75. To the reduced threaded end of the stud-pin 7 3 is applied the apertured lug 76 of abracket-piece 77 between which and the adjacent end of the boss are interposed the washers 73 and 79, the latter being of soft material such as felt to receive the impact of the boss 7 5 under the action of the spring 80 connecting a stud 81 upon the block 74L with a similar stud 82 tapped into the standard 2.

The block 74 is formed with a lateral wing 83 into which is tapped the shouldered screw-pin 84 affording a bearing for the rotary stop-member 85 and the ratchet-wheel 86 connected in driving relation therewith by means of steady pins 87 (Fig. [is represented in the drawings, the stop-member is provided with four peripherally spaced and upwardly extending stop-lugs 88 which are adapted to assume positions in register with the range of movement of the end of the push-rod 66 alternately with the intervening spaces, so that in the travel of the push-rod with the work-holder the pushrod is intercepted and evaded alternately by the stop-lugs.

The block 71 has a wing 89 extending therefrom oppositely from the wing 83 and affording at its end an abrupt shoulder 89* for engagement by a stud-pin 90 having a reduced and shouldered portion secured in position by a nut 91 in a lateral aperture of the flange 92 of a loose sleeve fitted to the cam-wheel shaft 28. The sleeve 93 enters an annular clearance recess in a collar 94: fixed upon the shaft 28 by means of a set-screw 95 and provided with an annular flange 96 having a series of apertures 97 adapted to be entered by the reduced lower end of the stud-pin 90.

The sleeve 93 is pressed downwardly by means of springs 98 interposed between the bottoms of sockets formed in said sleeve and the hub 99 of the cam-disk 100 fixed upon the shaft 28 by means of the set-screw 101.

In the rotation of the cam-shaft 28, the stud-pin 90 wipes against the end of the wing 89 of the block 7 4 and thrusts the lat ter forwardly in opposition to the spring 80 so as to cause the stop-member to meet the push-rod 66 and hasten the latters action in retracting the cutting and nipping blade preparatory to a thread-severing and nipping action. To maintain the block 7 1 against tilting upon the stud-pin '73 as a fulcrum, it has secured to its under side by a screw 102 a downwardly offset plate 103 between which and the wing 89 the adjacent side of the flange 96 is embraced.

The bracket-piece 77 carries a stud-screw 10 1 upon which is ournaled an angular pawl-lever having one arm 105 suitably shaped for engagement with the teeth of the ratchet-wheel 86 and another arm 106 connected by means of a spring 107 with an apertured stud 108 tapped into the depending arm 109 of a plural-armed rocker hav ing a hub 110 j ournaled upon the rock-shaft 111 which is mounted in bearings 112 of a bracket secured to the standard 2.

The pawl-lever arm 105 normally rests against an upturned stop-lug 7 7 of the bracket-piece 77, but is adapted to be retracted by the shift of the arm 106 in opposition to the spring 107 into the spring-clip 113 having its foot 11 1 secured by means of the screw 115 to the standard 2. As the stud-pin 90 travels around the cam-shaft 28, its engagement with the extremity 89* of the wing 89 ceases as its circular path of movement crosses the outer edge of the wing 89, thereby permitting the spring 80 to retract the block 7 1 into initial position and causing the ratchet-wheel 86 to engage the point of the pawl-lever arm 105 by which it is given a partial rotation. By this means, a stop-lug and an intervening space of the stop-member are alternately presented to the push-rod, so that they thread-cutting and nipping device is set for action upon the needle-thread and cord with less frequency than the stitching periods which are determined by a complete rotation of the cam-.

shaft 28.

Secured upon the rearward edge of the wing 83 by means of the screw 116 is the holding pawl-plate 117 which is pressed yieldingly upon the periphery of the ratchetwheel, its free edge serving by engagement with the ratchet teeth to prevent the stopmember from retrograde movement.

Secured upon the bottom of the wing 83 by the screw 118 is a spring 119 having an arm 119 adapted to press upon the inclined faces of the ratchetteeth to insure that the radial face of a ratchet-tooth will always engage the end of the pawl-plate 117 after each advance movement so as to insure the accurate positioning of the stopmember in proper register with the push rod 66.

It is evident that when the pawl-lever is shifted from its full-line operative position to its dotted-line inoperative position, as represented in Fig. 3, the stop-member is unaffected by the travel of the block 74 under the action of the stud-pin 90, and that the position in which the stop-member may be set determines whether the cutting device shall remain continuously inoperative or shall be operative for consecutive stitching periods. The position of circular adjustment of the stud-pin 90 in any of the apertures 97 determines the timing of its engagement with the carrier-block for the stop-member, and hence the instant in which the stopmember completes its travel. toward the work-holder.

As shown more particularly in Figs. et and 5, the rearward end of the push-bar 66 is notched on one side to form an abrupt shoulder 66 adapted for engagement with the side face of the latch-lever 120 adjacent the notch 121 therein which affords a shoulder adapted to rest upon the top of the rod 66; the latch-lever being fulcrumed upon the pin 122 sustained by the bracket 123 which is suitably secured upon the clamplever 24. The latch-lever 120 has upwardly and outwardly extending portions 124 and 125, and is pressed normally downward by means of a spring 126 coiled about the head of the fulcrum-pin 122.

The latch-lever extension 125 crosses the lateral crank-arm 127 having its hub 128 fixed upon the forward end of the rockshaft 111. Upon the rearward end of the rock-shaft 111 is secured by the set-screw 129 the hub 130 of a bent rearwardly extending arm 131 having in its extremity the centrally apertured boss 132 having fitted therein the forwardly projecting plunger pin 133 and provided with a socket contain.- ing the spring 13 1 interposed between the aportured cap 135 and a flange upon the pin 133. The arm 131 is drawn downwardly by means of a spring 136 connected at one end with an apertured stud 137 upon the boss 132 and at the other end with a similar stud 138 upon the stop-lever 13.

As disclosed more fully in the patent to E. B. Allen No. 885,310, of April 21, 1908, the plunger-pin 133 is adapted for engagement with the upper face of a collar 139 secured upon the spring-pressed plungerbar 12 as the upper end. of the plunger-bar performs its endwise movements under the action of the stopping cam 11 in arresting the main-shaft. The thread-cutting and nipping blade having been previously moved into retracted position and locked therein by the lever 120, as represented in dotted lines in 10, the operative connection of the plunger-pin 133 with the plunger-bar of the stop-motion causes the tilting of the arm 131 and the consequent rise of the arm 127 which is caused to engage the lateral extension 125 of the latch-lever and disconnect the latter from the push-rod 66, thereby permitting the latter under the action of its spring to impart to said blade an operative nipping and cutting action.

When the machine is at rest, its various parts are in the positions represented in Figs. 1, 2, 3, 1 and 9, the needle-thread a and cord 7) being held nipped between the bottom of the cross grooves 63 of the blade section 57 and the under face of the clamping foot 15 (Fig. 9). The fabric having been inserted in the work-holder by the lifting of the clamping foot, the stop-lever 13 is tilted to disengage the plunger-bar 12 from the stopping cam 11 and shift the driving belt from the loose to the fast pulle'y. The stitching progresses as usual along the first side of the buttonhole, the clamping foot traveling toward the left, or toward the front end of the machine 1) to its eXtreme advance position, there performing its side-shift and proceeding with its return movement.

After the first part of the return feed movement has been performed, the stud pin 90 in its circular movement with the camshaft 28 encounters the wing 83 of the carrier for the stop-member, as represented in dotted lines at the right in Fig. 5, and forces it forwardly to meet the bush-rod 66 which is being carried toward it in the travel of the work-holder which supports it. As a space between the stop-lugs 88 is presented for the passage of the pushrod, the latter remains in its initial position upon the work-holder, but upon release from the stud-pin, at the point represented in dotted lines at the left in Fig. 5, the carrier with the stop-member is drawn backwardly to initial position under the action of the spring 80.

In the retrograde movement of the stopmember, the engagement of the ratchet wheel 86 with the pawl-lever arm 105 gives such member a partial rotation so as to bring one of the lugs 88 into register with the push-rod 66, as represented in Fig. 5, but with the stop-member in initial position and therefore out of contact with the push-rod.

At the completion of its primary stitching period, the stop-motion is tripped and the latch-lever 120 shifted into releasing position, as represented in full lines in Fig. 10, but as the push-rod has not previously been operated to retract the nipping and cutting blade and store up actuating power in the spring 80, the actuation of the latchlever is ineffective in performing its normal function.

To produce a superposed corded overseam upon that previously applied to the fabric, the stop-motion is again actuated and the stitch-forming and feeding mechanism thus set in action for a second stitching period. During the travel of the workholder in the re-stitching of the second side of the buttonhole, the stop-member again advancestoward the push-rod, but this time presenting to it one of the stop-lugs 88, as represented in full lines in Fig. 5. In the simultaneous movements in opposite directions of the stop-member and the work holder, the push-rod is given a quick endwise movement to retract the cutting and nipping blade, the push-rod being locked in retracted position by means of the springpressed latclrlever 120. At the completion of the second stitching period, the stopmotion is tripped to arrest the stitch-forming and feeding mechanisms and the latchlever 120 is lifted, thereby releasing the push-rod 66 and causing it to effect, under the action of the spring 70, a threadcutting and nipping movement of the blade 56 57.

To insure the production of eflective stitching at the initial end of the buttonhole, it is important that the stitching thread and the cord be securely held by the nipping blade for at least a few stitches. It is also necessary that the cutting and nipping blade, which has a range of movement across the path of reciprocation of the needle,'be retracted before the completion of the second side-stitching operation so as to avoid collision with the needle.

In the production of long or moderatelength buttonholes, the retraction of the blade maybe effected by encounter of the spring-pressed push-rod with an abutment in permanently fixed position relatively to the travel of the work-holder, as represented in the said Patent No. 885,310; but in the production of very short length buttonholes special provision is required to insure the retraction with sufficient promptness of the utting and nipping blade.

In order that the blade 56 57 may occupy substantially the same retracted position for all adjustments of the machine for different length buttonholes, it is necessary that the stop-member invariably occupy relatively to the work-holder the same extreme advance position, wherein it becomes disengaged from the stud-pin 90, to produce the same effect upon the push-rod. As the speed of travel of the work-holder, and consequently of the push-rod, varies relatively to the speed of the feed-wheel corresponding with adjustments for different length buttonholes, it is requisite that the timing of the advance movement of the stop-member be correspondingly varied.

To this end, the stud-pin is adapted for insertion in any of the several apertures 97 to correspond with the size of the buttonhole to be produced. As represented in the drawings, the machine is adjusted to produce a buttonhole of substantially maximum length, and the stud-pin 90 is therefore positioned for imparting a delayed movement to the stop-member. hen the machine is fitted for buttonholes of minimum or intermediate length, the pin 90 will be placed in the more remote or the intermediate hole, respectively, so as to hasten to a greater or less extent, its action upon the rod 66. It is evidently unnecessary to provide a separate adjustment of the pin 90 for each length of buttonhole, as the degree of retractive movement of the rod 66 may obviously be varied to a certain limited extent, the adjustment of the means for effecting such movement being therefore required to be only approximate. v

At the end of the stitching operation, the directions of lead of the stltching thread from the fabric to the needle and of the cord to the guide t7 are slightly separated, and in the initial engagement of the blade-section 57 with the thread and cord they are drawn together by encounter of the divergent edges of the notch 62 into the inner end of which they move, being confined, in one stage of the operative movement of the blade, between said notch and the shoulder 64 formed in the end of the clamping foot 15, as represented in Fig. 7. As the blade continues its operative movement, the thread and cord are compressed together, the harder of the two beingusually em bedded in the other, as is somewhat imperfectly represented in Fig. 9. In this relation, the thread and cord are carried beneath the bottom of the foot 15 and securely clamped between the same and the bottom of the grooves 63 of the blade section 57, the portions of thread and cord beneath the same being sheared off at substantially the same time by the cutting-blade section 56 in conjunction with the sharpened edge of the removable section 53 of the foot.

While the omission of the thread and cord-cutting action, in the one or more stitching periods preceding the final stitching period, is advantageous particularly in eflecting the laying of two or more convolutions of a continuous cord around the button-hole, to insure against distortion in use, the prevention of the normal thread-cutting action at the end of each stitching period avoids leaving additional thread and cordends to mar the appearance of the work.

The four-point stop-member and the turning means therefor shown and described herein are designed, to time; the threadcutting actions to occur at the ends of alter nate stitching periods; but it is evident that the interval between severing actions may be increased by manual shift of the pawllever into and out of operative relation with the ratchet-wheel, or by varying the circumferential spacing apart of the circular series of stop-elements.

Vhile the stop-member is preferably formed with separated stop-lugs, it is ob vious that these stop-lugs need not be circumferentially disconnected, so long as the intervening portions are sufficiently depressed to prevent the endwise shift of the push-rod 66 to latching position so as to prematurely retain the cutting and nipping blade retracted in a stitching period preceding the final stitching period. Of course in an embodiment of the present improve ment in a machine wherein the spring-actuated thread-cutting device is tripped into action by the opening of the work-holder, the setting of the cutting device in opposition to its spring may be effected in the initial stitching period of a series, the cutting device remaining inactive throughout one or more complete stitching periods and until the work-holder is opened for removing or shifting the work.

From the foregoing description, it is evident that the present improvement is susceptible of embodiment in widely different forms depending upon the character of the work to be performed. The thread-cutting element is not necessarily mounted upon the work-holder, nor is the stop-member required to perform rec-iprocatory movements toward an d from the same in the application of the device to certain conditions different from those for which the present embodiment of the improvement is designed.

Having thus set forth the nature of the invention, what I claim herein is 1. In a sewing machine, in combination, stitch-forming mechanism, feeding mechanism including feed-actuating means for producing relative feeding movements between the stitch-forming mechanism and the worl-c, a thread-cutting element movable across the range of action of the stitchforming mechanism, means for imparting thereto cutting; movements, and retracting means for said thread-cutting element having a plurality of separate trains of operative connections with the feed-actuating means.

2. In a sewing machine, in combination, stitch-forn'iing mechanism, a traveling work-holder, feeding mechanism connected therewith, a spring-actuated reciprocatory thread-cutting element mounted upon and traveling with the work-holder and movable across the range of action of the stitchforming mechanism, and means connected with the feeding mechanism independently of its connection with the work-holder for retracting the cutting element preparatory to a cuttin action.

3. In a sewing machine, in combination, stitch-forming mechanism, a traveling work-holder, feeding mechanism connected therewith, a spring-actuated reciprocatory thread-cutting element mounted upon the work-holderand movable across the range of action of the stitch-forming mechanism, and means connected with the feeding mechanism independently of and acting in opposition to the travel of the work-holder for retracting the cutting element preparatory to a cutting action. I

4L. In combination with a sewing machine comprising stitch-forming and feeding mechanisms with means for operating them to produce in a complete cycle of operation thereof stitching disposed in a predetermined pattern, a thread-cutting element, and automatically controlled means acting there on once only in a plurality of consecutive cycles of operation to efiect the cutting of the thread.

:5. 1n combination with a sewing machine comprising stitch-forming and mechanisms with means for operating them to produce in a complete cycle of opera-- tion thereof stitching disposed in a prede termined pattern, a thread-cutting element, and actuating means therefor automatically controlled to effect cutting actions of less frequency than that of said cycles of operation.

6. In combination with a sewing machine comprising stitch-forming and feeding mechanisms with means for operating them to produce in acomplete cycle of operation thereof stitching disposed in a predetermined pattern, a thread-cutting element, ac-

comprising feeding tuating means therefor, and means for effecting changes in the frequency of operation of said actuating means relatively to said cycles of operation.

7. In combination with a sewing machine stitch-forming and feeding mechanisms with means for operating them to produce in a complete cycle of operation thereof stitching disposed in a predetermined pattern, a thread-cutting clement, actua means therefor including a springpre d member and a latch acting thereon, and automatically controlled means acting to effect with less frequency than that of said cycles of operation the operation of said thread-cutting element to cut the thread.

8. In combination with a sewing machine comprising stitch-forming and feeding mechanisms with means for operating them to produce in a complete cycle of operation thereof stitching disposed in a predetermined pattern, a thread-cutting element, actuating means therefor including a reciproc-atory member, a spring connected there with and a latch acting upon said member, means acting at less frequent intervals than said cycles of operation in storing power in said spring, and means for tripping said latch to effect a cutting action.

9. In a sewing machine, in combination, stitch-forming mechanism, a thread-cutting element, actuatin means therefor including a reciprocatory member, a' spring connected therewith and a, latch acting upon said member, means for storing power in said spring at less frequent intervals than the consecutive periods of operation of the stitch-forming mechanism, and means acting with the same frequency as the consecutive periods of operation of the stitch-forming mechanism for effecting the tripping of said latch to effect a cutting action.

10. In a sewing machine, in combination, stitch-forming mechanism, a traveling workholder, a thread-cutting element, actuating means therefor including reciprocatory element connected with and normally partaking of the movements of the work-holder, a stop-member adapted for engagement with saic. rcciprocatory element, and means for imparting to said stop-member operative movements simultaneous with and opposite to the travel of said work-holder.

11. In a sewing machine, in combination, stitclrforming mechanisn'l, a traveling worlc holder, a thread-cutting element, actuating means therefor including a reciprocatory element carried by said work-holder, a stop member adapted for engagement with said reciprocatory element, and means for imparting to said stop-member operative movements simultaneous with and opposite to the travel of said work-holder.

12. In a. sewing machine, in COll'llQlllillllOll, stitch-forming mechanism, a traveling workholder, a thread-cutting element, actuating means therefor including a springpressed push rod connected with and normally partaking of the movements of the work-holder, a stop-member adapted for engagement with said push-rod, and means for imparting to said stop-member operative movements simultaneous with and opposite to the travel of said work-holder.

18. In. a sewing machine, in combination, stitch-forming mechanism, a traveling workholder, a thread-cutting element, actuating means therefor including a reciprocatory element connected with and normally partaking of the movements of the work-holder, a stop-member adapted for engagement with said reciprocatory element, and means for imparting to said stop-member operative movements simultaneous with and opposite to the travel of said work-holder, said stopmember being mounted for movement crosswise of the direction of travel of the workholder.

14. In a sewing machine, in combination,

stitclrforming mechanism, a traveling workholder, a thread-cutting element, actuating means therefor including a reciprocatory element connected with and normally partaking of the movements of the work-holder, a stop-member adapted for engagement with said reciprocatory element, means for imparting to said stop-member operative movements simultaneous with and opposite to the travel of said work-holder, and means for imparting to the stop-member lateral movements transversely of the direction of travel of the work-holder.

15. In a sewing machine, in combination, stitch-forming mechanism, a traveling workholder, a thread cutting element, actuating means therefor including a reciprocatory element connected with and normally partaking of the movements of the work-holder, a rotary stop-member having a plurality of circularly arranged and circumferentially spaced stop elements adapted for engage ment with said reciprocatory element, means for imparting to said stop-member operative movements simultaneous with and opposite to the travel of said work-holder, and means for turning said stop-member to move said stop elements into and out of register with said reciprocatory element.

16. In a sewing machine, in combination, stitc-lrforming mechanism, a traveling workholder, a thread-cutting element, actuating means therefor including a reciprocatory element connected with and normally partaking of the movements of the work-holder, a reciprocatory carrier, a stop-member mounted thereon for rotation and adapted for engagement with said reciprocatory element, means for imparting to said carrier reciprocatory movements simultaneous with and opposite to the travel of said workholder, a ratchet-wheel connected with the stopmember, and a pawl mounted upon a fixed support and adapted for operative engagement with said ratchet-wheel.

17. In a sewing machine, in combination, stitch-forming mechanism, a traveling work holder, a thread-cutting element, actuating means therefor including a reciprocatory element, connected with and normally partaking of the movements of the work-holder, a reciprocatory carrier, a stop-member mounted thereon for rotation and adapted for engagement with said reciprocatory element, means for imparting to said carrier reciprocatory movements simultaneous with and opposite to the travel of said workholder, a ratchet-wheel connected with the stop-member, a pawl mounted upon a fixed support and adapted for operative engagement with said ratchet-wheel, and a detent sustained by said carrier in operative e11- gagement with the ratchet-wheel.

18. In a sewing machine, in combination, stitch-forming mechanism, a traveling workholder, a thread-cutting element, actuating means therefor including a reciprocatory element connected with and normally partaking of the movements of the work-holder, a reciprocatory carrier, a stop -member mounted thereon for rotation and adapted for engagement with said reciprocatory element, means for imparting to said carrier reciprocatory movements simultaneous with and opposite to the travel of said workholder, a ratchet-wheel connected with the stop-member, a pawl mounted upon a fixed support and adapted for operative engagement with said ratchet-wheel, a detent sus tained by said carrier in operative engagement with the ratchet-wheel, and a spring yieldingly acting upon said ratchet-wheel in opposition to said pawl for pressing it into stopping relation with said detent.

19. In a sewing machine, in combination, stitch-forming mechanism, a traveling workholder, a thread-cutting element, actuating means therefor including a reciprocatory element movable independently of the workholder, a carrier mounted for movement in the direction of travel of the work-holder, a stop-element mounted thereon and adapted for engagement with said reciprocatory element, a spring for maintaining said carrier yieldingly in an initial position, a rotary shaft, and a crank element carried by said shaft and adapted for periodical engagement with said carrier.

20. In a sewing machine in combination, stitch-forming mechanism, a traveling workholder, a thread cutting element, actuating means therefor including a reciprocatory element movable independently of the workholder, a carrier mounted for movement in the direction of travel of the work-holder, a stop-element mounted thereon and adapted for engagement with said reciprocatory element, a spring for maintaining said carrier yieldingly in an initial position, a rotary shaft, and a crank element carried by and circularly adjustable upon said shaft and adapted for periodical engagement with said carrier.

21. In a sewing machine, in combination, stitclnforming mechanism, a traveling workholder, a rotary shaft, a feed-wheel thereon operatively connected with said workholder, a thread-cutting element, actuating means therefor including a reciprocatory element sustained by and movable independently of the worlcliolder, a carrier mounted independently of and movable in the direc tion of travel of the work-holder, a stop-element mounted thereon and adapted for engagement with said reciprocatory element, a spring for maintaining said carrier yieldingly in an initial position, and a crank element carried by said shaft and adapted for periodical engagement with said carrier.

22. In a sewing machine, in combination, stitcl1forming mechanism including a re ciprocating needle, feeding mechanism, a work-holder formed with a needle-aperture having a thread-nipping face and an adja cent abrupt shoulder at one side of the needle-path, a cord-guide maintaining a po sition in advance of the needle relatively to the direction of feed, a reciprocatory threadnipping blade mounted on the work-holder for movement across the needle-aperture and formed in one edge with a flaring notch adapted to embrace and compress together the needle-thread and the cord and to carry them into engagement with said shoulder of the needle-aperture, and actuating means for said blade.

23. In a sewing machine, in combination, stitch-forming mechanism including a reciprocating needle, feeding mechanism, a workholder formed with a needle-aperture having a thread-nipping face and an adjacent abrupt shoulder at one side of the needlepath, a cord-guide maintaining a position in advance of the needle relatively to the direction of feed, a reciprocatory thread-nipping blade mounted on the work-holder for movement across the needle-aperture and formed in one edge with a flaring notch adapted to embrace and compress together the needlethread and the cord and to carry them into engagement with said shoulder for the needle-aperture, a shallow transverse channel being provided between the thread-engaging faces of the work-holder and said blade, and actuating means for said blade.

24. In a sewing machine, in combination, stitch-forming mechanism, a work-holder, feeding mechanism for producing between the stitch-forming mechanism and the workholder relative traveling movements in a defined path, a thread-cutting element movable across the range of action of the stitchforming mechanism, actuating means therefor including a spring-pressed reciprocatory member normally partaking of said relative feeding movements, and a stop-element movable transversely of the direction of said relative travel and means for shifting it alternately, in consecutive cycles of operation of said feeding mechanism, into and out of the path of movement of said reciprocatory member.

25. In a sewing machine, in combination, stitch-forming mechanism, a traveling workholder, feeding mechanism connected with and adapted to impart to the work-holder its traveling movements, a thread-cutting element movable across the range of action of the stitch-forming mechanism, actuating means therefor including a spring-pressed reciprocatory member connected with and normally partaking of the traveling movements of the work-holder, and a stop-element mounted independently of and adapted for movement crosswise of the travel of the worltholder and means for shifting it alternately, in consecutive cycles of operation of said feeding mechanism, into and out of the path of movement of said reciprocatory member.

26. In a sewing machine, in combination, stitch-forming mechanism, a work-holder, feeding mechanism for producing between the stitch-forming mechanism and the work holder relative traveling movements, a thread-cutting element movable across the range of action of the stitch-forming mechanism, actuating means therefor including a spring-pressed reciprocatory member normally partaking of said relative feeding movements, a stop-element movable transversely of the direction of said relative travel and into and out of the path of movement of said reciprocatcry member, and means for imparting to said stop element transverse shifting movements alternately into and out of the range of action of said reciprocatory member.

27. In combination with a sewing machine comprising stitch-forming and feeding mechanisms with means for operating them to produce in each one of a series of complete cycles of operation thereof stitching disposed in a predetermined pattern, a thread-cutting element, actuating means therefor, and means for effecting the operation of the thread-cutting element at the completion of one of said cycles of operation and for insuring the inaction thereof in the cycle next preceding it.

28. In a sewing machine, in combination, stitch-forming mechanism, feeding mechanism for producing relative traveling movements between the same and the work, a stop-motion for determining the period of action of the stitch-forming and feeding 1Q aminae mechanisms, a thread-cutting element, ao tu In testimony whereof, I have signed my atlng means therefor, and means operatlvely name to this specification, 1n the presence of connected- Wlth said stop-motion for effecttwosubscrlblng wltnesses.

ing the operation of the thread-cutting ele- ALFRED R. \VOOD. ment at the completion of one stitching pe- Vitnesses: riod and for insuring the inaction thereof in STANLEY N. SMITH,

the stitching period next preceding it. H. C. FAULKNER. 

